1. Field of the Invention
The present invention relates to a system for detecting an abnormality of a yaw rate sensor for detecting a yaw rate of a vehicle, and a system for detecting an abnormality of a lateral acceleration sensor for detecting a lateral acceleration of the vehicle.
2. Description of the Related Art
To detect the abnormality of the yaw rate sensor, it is a conventional practice to determine that the yaw rate is abnormal when the value detected by the yaw rate sensor exceeds an upper limit value or a lower limit value, and to determine the abnormality of the yaw rate sensor by comparison of the yaw rate presumed from a difference between left and right wheel speeds with the value detected by the yaw rate sensor.
In the technique for determining whether the yaw rate sensor is abnormal based on whether the value detected by the yaw rate sensor exceeds the upper or lower limit value, it is impossible to detect a state in which the neutral point of the yaw rate sensor is normal, but the sensitivity is abnormal. In the technique for determining whether the yaw rate sensor is abnormal by the comparison of the yaw rate presumed from a difference between the left and right wheel speeds with the value detected by the yaw rate sensor, the yaw rate presumed from the difference between the left and right wheel speeds is inaccurate when the vehicle is traveling on a rough road or on a road surface having a low friction coefficient, on which the wheel is liable to slip. For this reason, it is impossible to determine the abnormality of the yaw rate sensor with good accuracy.